I have an Excel Workbook I want to distribute. I want to copy protect it. I
want to be able to email/post it to users, on first use they will be
prompted to enter a code, distributed with the workbook, they will then
connect to the web, and receive an 'unlock' key.

The web side of things will need to keep count of how many licences they
have bought.

Any ideas? I thought of doing this via a small vb app, then using one of the
many 3rd party protection systems to protect the vb app, which will in turn
open the workbook (perhaps with an encrypted password?).

Security isn't massively important, this doesn't need to be to banking
standards. I just want to track who has paid for it and prevent casual
copying. It isn't a mass market product to I doubt it'll appear on Warez
sites. The data in the spreadsheet isn't important, it's the structure and
formulae etc. The data isn't sensitive.

Yours, Mike MacSween

copy protection on workbooks is so weak, there isn't a lot of use in getting
carried away with it. Any VBA based solution can be overcome by disabling
macros for a start. Any password can be bypassed with a password cracker -
many of which are available on the web.

Files can be copied using Explorer/the command window, so not sure how you
intend to copy protect it.

If the structure and the formulas are what is important, that would be the
hardest to protect if the user needs to able to type things in the workbook.
You would need to put critical logic into a compiled DLL or com addin or
something like that.

--
Regards,
Tom Ogilvy

"Mike MacSween" wrote in message
...
I have an Excel Workbook I want to distribute. I want to copy protect it.
I
want to be able to email/post it to users, on first use they will be
prompted to enter a code, distributed with the workbook, they will then
connect to the web, and receive an 'unlock' key.

The web side of things will need to keep count of how many licences they
have bought.

Any ideas? I thought of doing this via a small vb app, then using one of
the
many 3rd party protection systems to protect the vb app, which will in
turn
open the workbook (perhaps with an encrypted password?).

Security isn't massively important, this doesn't need to be to banking
standards. I just want to track who has paid for it and prevent casual
copying. It isn't a mass market product to I doubt it'll appear on Warez
sites. The data in the spreadsheet isn't important, it's the structure and
formulae etc. The data isn't sensitive.

Yours, Mike MacSween

Mike MacSween wrote:
I have an Excel Workbook I want to distribute. I want to copy protect it. I
want to be able to email/post it to users, on first use they will be
prompted to enter a code, distributed with the workbook, they will then
connect to the web, and receive an 'unlock' key.

Probably best to write some custom code that can then output Excel files
(if you really want to be able to use Excel).

"Mike MacSween" wrote in message . ..
I have an Excel Workbook I want to distribute. I want to copy protect it. I
want to be able to email/post it to users, on first use they will be
prompted to enter a code, distributed with the workbook, they will then
connect to the web, and receive an 'unlock' key.

The web side of things will need to keep count of how many licences they
have bought.


This is entirely feasible. I would suggest that you impliment this
solution with Macros and protect it with standard MS Excel password
protection.


Any ideas? I thought of doing this via a small vb app, then using one of the
many 3rd party protection systems to protect the vb app, which will in turn
open the workbook (perhaps with an encrypted password?).

Security isn't massively important, this doesn't need to be to banking
standards. I just want to track who has paid for it and prevent casual
copying. It isn't a mass market product to I doubt it'll appear on Warez
sites. The data in the spreadsheet isn't important, it's the structure and
formulae etc. The data isn't sensitive.

Yours, Mike MacSween

If security were more important, you might consider creating an Excel
Add In.


--

http://www.intertek.org.uk

If security were more important, you might consider creating an
Excel
Add In.

A standard Excel add-in (XLA file) is no more secure that a
workbook. For real security, you need to use an XLL or a COM
add-in.


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com



"Alert" wrote in message
om...
"Mike MacSween"
wrote in message
. ..
I have an Excel Workbook I want to distribute. I want to copy
protect it. I
want to be able to email/post it to users, on first use they
will be
prompted to enter a code, distributed with the workbook, they
will then
connect to the web, and receive an 'unlock' key.

The web side of things will need to keep count of how many
licences they
have bought.


This is entirely feasible. I would suggest that you impliment
this
solution with Macros and protect it with standard MS Excel
password
protection.


Any ideas? I thought of doing this via a small vb app, then
using one of the
many 3rd party protection systems to protect the vb app,
which will in turn
open the workbook (perhaps with an encrypted password?).

Security isn't massively important, this doesn't need to be
to banking
standards. I just want to track who has paid for it and
prevent casual
copying. It isn't a mass market product to I doubt it'll
appear on Warez
sites. The data in the spreadsheet isn't important, it's the
structure and
formulae etc. The data isn't sensitive.

Yours, Mike MacSween

If security were more important, you might consider creating an
Excel
Add In.


--

http://www.intertek.org.uk

Hello Chip,

A standard Excel add-in (XLA file) is no more secure that a
workbook.

Is it true that Excel 97 Add-ins even without VBA-Passwords are secure? Do
you know how securing the workbook/addin was done in Excel 97. I hate to say
that but I am too young to know ;)

best regards

arno

I'm not Chip, but until he returns...

Excel Addins (*.xla's) are not secure at all--and without a password, even the
most mildly curious will be able to see/modify your code.

Addins with passwords are only slightly better. The passwords will stop the
honest--but not the determined. And there are password breakers all over the
internet. With enough money (about 50 USD, IIRC), anyone can see and modify
your code.

That's why Chip wrote: For real security, you need to use an XLL or a COM
add-in.

These are compiled (a lot like regular programs (*.exe's)) and I'm not sure
there is a human who can read those.



arno wrote:

Hello Chip,

A standard Excel add-in (XLA file) is no more secure that a
workbook.

Is it true that Excel 97 Add-ins even without VBA-Passwords are secure? Do
you know how securing the workbook/addin was done in Excel 97. I hate to say
that but I am too young to know ;)

best regards

arno

--

Dave Peterson

"Dave Peterson" wrote in message
...
I'm not Chip, but until he returns...

Excel Addins (*.xla's) are not secure at all--and without a password, even
the
most mildly curious will be able to see/modify your code.

Addins with passwords are only slightly better. The passwords will stop
the
honest--but not the determined. And there are password breakers all over
the
internet. With enough money (about 50 USD, IIRC), anyone can see and
modify

Not talking about this particular case, but I frequently hear the 'you can
buy a password cracker so the password is useless' statement. I bought one
yesterday and ran it against the file open password on an Excel file. I'd
used a deliberately obscure, completely non alphanumeric long password. It
went through the dictionary attack (and failed, obviously) in 5 seconds. It
then started on the brute force attack (well, a sort of refined brute
force). I turned it off after a few hours when it was still running
bXXXXXXX. As a matter of fact when I tried to set it up to so that it would
(eventually) get my password it complained that it would take too long, and
shortened the length of the passwords it would try, basically guaranteeing
it wouldn't ever get mine. It estimated 45,000 days!

I think it's a myth. Sure, if somebody uses their first name+last name as a
password, that's easy to crack. I've 'cracked' that often enough when I've
needed to log on as a user and I know their name. But I really don't think
that passwords are as useless as everybody says. If you know how to make a
very strong password then you can do a lot.

Mike